Authorities find 14 guns in Trump rally shooter's home, 2 explosive devices in his car

A U.S. senator briefed on the investigation into the Trump rally shooter said authorities found 14 guns inside the 20-year-old's home and two explosive devices in his car.

Republican Sen. John Barrasso of Wyoming confirmed the findings in a phone call with Scripps News, also saying that investigators discovered the gunman had two phones and a drone in his vehicle.

Barrasso was among the members of Congress whom the FBI and Secret Service privately briefed about their investigation into the lone shooter who fired multiple rounds at former President Donald Trump's rally in Butler, Pennsylvania, on Saturday. Trump and two attendees were injured, and one man died in the aftermath.

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Another source familiar with the briefing told Scripps News that investigators said they'd recovered thumb drives, a computer and a remote detonator that belonged to the shooter. And on his laptop, there were searches of the Butler rally, the Democratic National Committee and President Biden.

But law enforcement officials are still trying to uncover the motive behind the assassination attempt, with the investigation so far revealing the shooter had no type of manifesto, history of mental health issues or a criminal past.

Despite the briefing addressing the investigation into the gunman, Barrasso told Scripps News that he and other lawmakers were frustrated with the lack of information into the Secret Service's alleged security failures at the rally. He described it as a "reading of talking points, stonewalling, and then cutting off questions after just a few questions."

The senator told Scripps News this led to a heated confrontation between angry GOP senators and Secret Service Director Kimberly Cheatle during the third night of the Republican National Convention Wednesday. Barrasso said she didn't respond to a number of questions that he wanted to ask, including why the rooftop the gunman shot from nearly 150 yards away from the former president wasn't secure.

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A Secret Service source confirmed to Scripps News that the agency did not sweep the rooftop because it was outside of their perimeter, leaving it to local enforcement. But a spokesperson for the Pennsylvania State Police said its department provided "all resources" that the Secret Service requested for Trump's rally, including 30 to 40 troopers who helped secure the inside perimeter, and that it "was not responsible for securing" the rooftop.

Cheatle said the Secret Service is participating in the president's internal review into the assassination attempt. She's also been subpoenaed by the House Oversight and Accountability Committee to testify before a public hearing. A spokesperson for the committee confirmed to Scripps News on Wednesday that Cheatle has agreed to comply with the subpoena and appear for a hearing on July 22.

"The Secret Service is working with all involved federal, state and local agencies to understand what happened, how it happened, and how we can prevent an incident like this from ever taking place again," Cheatle said in a statement earlier this week. "We understand the importance of the independent review announced by President Biden yesterday and will participate fully. We will also work with the appropriate Congressional committees on any oversight action."